The present inventive concept disclosed herein relates to a piezoelectric power generator generating power by itself, and more particularly, to an impact-type piezoelectric micro power generator.
Portable electronic devices generally used in daily lives or production environments may include a battery or a fixed power supply as a power source. Particularly, in the case of batteries, it is necessary to periodically charge or exchange according to lifespan thereof. Maintenance cost occurs when changing batteries, and environmental pollution is generated when disposing them. Accordingly, recently, instead of power sources including batteries or fixed power supplies, necessity of self-powered electronic devices generating power by itself and operating has been increased. Particularly, as sensing and monitoring devices have been developed to be wireless and to consume low power, it is necessary to develop micro power generators capable of supplying power by using an energy harvesting principle collecting or harvesting electric energy from surrounding environments. These may have a modular form or a single body shape and may be used for electronic devices function as independent power sources or emergency power sources.
Micro power generation using energy harvesting may have great technical and economical effects when being used in places in which environmental energy always exist, for example, vehicles, motors, railways, flights, roads, bridges, air conditioning systems, and automated production lines. For example, a tire pressure monitoring system (TPMS) that is a wireless sensor module monitoring a pneumatic tire pressure state in real time may be installed together with a micro power generator. In this case, the micro power generator converts mechanical energy generated in the tire into electric energy to provide power to the wireless sensor module for the vehicle without using an external power supply unit.
Piezoelectric micro power generators may convert physical energies such as vibrations, impacts, rotational forces, inertial forces, pressure, and fluid flows into electric energies. Mostly, as energy converting materials of piezoelectric micro power generators, piezoelectric materials are used. Piezoelectric materials may generate electrical charges when mechanical strain applied to the piezoelectric body. Accordingly, electrical charges are collected by using electrodes, thereby generating electric energies.